VST's suddenly running up CPU usage...

homerjsim · Post by **homerjsim** » Sun Feb 29, 2004 4:00 pm

Anyone have this problem?
I have a lot of vst plugins inserted but in bypass mode (just to preserve the x-y assignments I need for certain things, etc). I use free stuff like whix, skidder/scrubby, ohmboyz OhMyGod, etc...

A lot of times, after about 4-5 minutes a particular VST instance will cause the CPU to suddenly go up to 80-90%. - if I put that instance into bypass, the usage comes back down, but until I relaunch Live, that particular instance will cause the CPU to spike back up the second I take it ou of bypass - even*when*Live's*stopped!!!

I'd say I have an average of 3 bypassed plugins per my 8 default tracks, for a total of 24 or so - but again, they're usually all in bypass!!!

Anyone else have this problem???

(I have a 2.6 gHz P4 Viao, XP home, 768 mB ram, RME Hammerfall...)

Thanks in advance,
Brian

Cosmo · Post by **Cosmo** » Tue Mar 02, 2004 11:47 pm

I have the same problem!!! I was playing with live for hours, adding more samples and plugins, and the CPU stayed at 27% for all the time I was playing. At the end of the session, I pressed "stop all clips" and after 2 minutes the CPU meter suddenly jumped up to 100%!!! But it was working fine for hours before!!! HELP!!!!

ducktail · Post by **ducktail** » Sat Mar 06, 2004 10:45 pm

Join the club. I have been gouging at this problem for 4 months now. I'll tell you what it isn't;

-not drivers for audio cards.
-not USB peripherals
-not drive speed
-not CPU speed (it happens on a 3.06 ghz)
-it's not Live (you can do it with SX2 as well)
-Ableton has no idea what causes it.
-it only happens on PCs, not Macs

May possibly be IRQ stacking or hyperthreading.

If you ever figure it out, email me at opticalthunder at hotmail.com

Guest · Post by **Guest** » Mon Mar 08, 2004 6:08 pm

it's been my understanding that free or cheap VST's jack up your CPU usage, no matter how good your computer is. so it makes sense to me that things would get messed up if you're using 24 free VST's. maybe i'm wrong though.

abstract_q · Post by **abstract_q** » Tue Mar 09, 2004 11:45 am

hello
i've the same problem...sometimes the cpu load jump from 20%-30% to 120% or more and i hear distorted sound and i've difficult to stop Live3. When Live is stopped after some seconds the cpu load reourn to the real value... this make me crazy! If I restart playng at he same bar all is ok for only 1 minut or less...than the same problem!

Do you think the problem are the vst instruments?...i must try.

ciao!

abstract_q · Post by **abstract_q** » Tue Mar 09, 2004 4:32 pm

hi
i've now contacted the ableton support.
they suggest me that the vst effects can generate this kind of problems.
this evening i try to eleiminate vst eff. from my project and i test if it work.
ciao

Martyn · Post by **Martyn** » Tue Mar 09, 2004 10:26 pm

Get the "normaliser" plugin from www.digitalfishphones.com
It's probably a de-normalisation problem caused by some older plugins, Running the normaliser plug in the master section should cure it.

brecht · Post by **brecht** » Wed Mar 10, 2004 4:00 am

Martyn wrote:Get the "normaliser" plugin from www.digitalfishphones.com
It's probably a de-normalisation problem caused by some older plugins, Running the normaliser plug in the master section should cure it.

wow. that's a creepy P4 problem, and I'm surprised I never heard about it before. to quote from the site martyn posted:

"The problem happens when the CPU (precisely: the floating point unit (FPU) inside of it) detects extremely small numbers and wishes to process them with the same precision as usual. Then it switches into 'denormal' mode which is another way of representing small floating point numbers with the available bit range. Converting between the two states takes a lot of time for the FPU and thus might cause heavy load jumps....
Currently, the Pentium 4 processor seems highly addicted to denormalisation. It turned out that its threshold is actually very much higher than of former Pentium types. Plugins that used to work fine with older CPUs might slow down the entire system when used with a P4."

abstract_q · Post by **abstract_q** » Wed Mar 10, 2004 11:38 am

hi
i think this is not only a P4 problem. I'm using a P3... for my experience this problem is random. There is not a real and concrete reason sometimes i play my live set without problems and sometime the same set doesnt works.
now i should buy another laptop. I hope....
ciao

Martyn · Post by **Martyn** » Wed Mar 10, 2004 9:33 pm

Did the "normalizer" plug cure the problem? I've only experienced a similar thing happening with an Ohmforce filter, it was a bit jittery in some other hosts too so I binned it and used a different filter. I never thought about the de-normal thing till recently.

spydear · Post by **spydear** » Thu Mar 11, 2004 2:02 pm

try to get the latest version of your fxs it soled the problem for me

VST's suddenly running up CPU usage...

VST's suddenly running up CPU usage...

get an update on your efxs